JPH07258356A - Production of modified propylene polymer, and modified propylene polymer composition - Google Patents

Abstract

PURPOSE:To obtain a modified propylene polymer which is excellent in reaction extrusion processability by an extruder, etc., and has high conversion and grafting ratio of a vinyl monomer. CONSTITUTION:A powdered propylene polymer with a specific surface area of 0.1m<2>/g or higher is used in the process for producing a modified propylene polymer wherein a propylene polymer is mixed with a vinyl monomer and kneaded at its m.p. or higher to polymerize the monomer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention makes it easy to impregnate a vinyl-based monomer at room temperature, has an excellent reactive extrusion processability of a propylene-based polymer in an extruder, and has a high polymerization rate of the vinyl-based monomer. Regarding a method for producing a modified propylene-based polymer having a high graft ratio,
In particular, the present invention provides a method for producing a modified propylene-based polymer having excellent rigidity, which is useful as a packaging material / container material.

[0002]

2. Description of the Related Art Polypropylene is low in cost and excellent in mechanical strength, heat resistance, oil resistance, electric characteristics, etc.
Widely used for various purposes such as films, fibers, and molded products.

However, polypropylene is
It is inferior to other vinyl polymers, especially polystyrene, in terms of sheet processability and surface characteristics. For example, in the field of packaging containers, polypropylene has a lower rigidity than polystyrene and has a drawback that sheet processing is difficult. However, on the other hand, it has advantages such as superior heat resistance, oil resistance, and moisture resistance to polystyrene. Therefore, if a molding material having a good balance between the advantages of polypropylene and the advantages of polystyrene can be made, it is expected that it will be possible to use it in the fields of application that were previously unusable.

Therefore, attempts have been made to blend polypropylene with polypropylene resin or to polymerize styrene in the presence of propylene polymer. JP-A-59-2
Japanese Patent No. 17742 discloses a modified polypropylene obtained by polymerizing a styrene monomer in an aqueous suspension system in the presence of a propylene polymer. Further, in JP-A-4-213313, a modified polypropylene obtained by activating a granular propylene-based polymer with a peroxide and then adding a styrene-based monomer, and polymerizing the propylene-based polymer under a condition capable of maintaining the granularity by a solid phase system. Is disclosed.

However, since polypropylene and polystyrene are incompatible with each other and the interfacial adhesion between the two resins is poor if they are simply blended, the polystyrene part is insufficiently dispersed and phase separation occurs, resulting in a molded product. Mechanical properties such as transparency, rigidity, and impact resistance are unsatisfactory and are not practical. When the styrene-based monomer is polymerized in an aqueous suspension system or a solid-phase system in the presence of powdery propylene-based polymer, steps such as blocking prevention, control of polymerization temperature, and drying of the product may be performed. It became complicated and was difficult to industrialize as a general-purpose polymer.

As described above, the introduction of the styrene-based polymer into the propylene-based polymer by the conventional method has the following effects on the polymer performance.
Or it was not satisfactory in manufacturing. This is due to the insufficient dispersion of polystyrene in the propylene polymer. And in order to sufficiently disperse polystyrene, the presence of a graft polymer of a propylene-based polymer and polystyrene is desirable, but polypropylene is
In the first place, since it is a highly crystalline material, first, it has a high melting point, and then it does not dissolve in the styrene-based monomer.
It is considered that this is because it is difficult to form a graft polymer.

[0007]

Therefore, the present inventors intend to solve the above-mentioned invention in order to solve the above-mentioned drawbacks in the conventional method, that is, the transparency, rigidity and moldability. As a result of intensive research focused on the subject, various properties have already been obtained by polymerizing an aromatic vinyl-based monomer in the presence of a propylene-based polymer in a molten state such as in an extruder. The inventors have found that an aromatic vinyl-based monomer graft polymer having excellent properties can be obtained and can be easily produced industrially, and filed an application.
(JP-A-4-359910, JP-A-5-1559)
47, JP-A-5-239158)

However, in these methods, when the propylene-based polymer is supplied to an extruder or the like and melted, and then a vinyl monomer is injected from the middle of the extruder or the like by a liquid injection pump to perform melt-kneading polymerization. However, the impregnation of the vinyl-based monomer at room temperature is insufficient, so that the supply of the propylene-based polymer to the extruder is not smooth, and the resulting modified propylene-based polymer has insufficient compatibility. I knew that there was.

When the propylene-based polymer and the vinyl-based monomer are premixed and then melt-kneaded and polymerized by an extruder,
It takes a long time to impregnate a propylene-based polymer with a vinyl-based monomer at room temperature, and when a propylene-based polymer having a small specific surface area such as pellets is used as the propylene-based polymer, the vinyl monomer is sufficiently propylene-containing. It is not adsorbed on the polymer and the vinyl monomer separates and flows out, or the screw slips when feeding to the extruder and it is difficult to bite into the extruder, that is, the reaction of the propylene polymer in the extruder. Extrudability was poor. Further, because of this, the modified propylene-based polymer becomes inhomogeneous and the transparency is inferior, the polymerization rate of the vinyl polymer in the modified propylene-based polymer, the grafting rate, etc. are sufficient and the vinyl monomer-derived component is used. I couldn't make it higher.

Therefore, the problem to be solved by the present invention is to improve the impregnability of vinyl monomers, which is a drawback of the prior art, and the reactive extrusion processability of propylene polymers in an extruder, that is, impregnated propylene. A method for producing a modified propylene-based polymer, which has excellent feedability to an extruder of a system-based polymer, a high polymerization rate of a vinyl-based monomer, and a high graft ratio and also a high component derived from a vinyl monomer, can be found. ,transparency,
It is an object of the present invention to provide a highly practical modified propylene-based polymer composition having a large amount of a vinyl monomer component which is excellent in rigidity and the like.

As a result of detailed studies, the inventors of the present invention adsorbed a vinyl monomer by using a propylene polymer having a specific surface area when producing the modified propylene polymer. It is easy and can contain a large amount of vinyl-based monomers, and the melt-kneading polymerization reaction of the preliminary mixture is the first to allow reactive extrusion processability of the propylene-based polymer in an extruder, that is, an extruder or the like. It has excellent feedability to the continuous kneading machine, high content of vinyl monomer-derived components,
The inventors have found that a good balance of physical properties is achieved with a high polymerization rate and a high graft rate, and have completed the present invention.

[0012]

That is, according to the present invention, a vinyl monomer is premixed with a propylene polymer, and the preliminary mixture is kneaded at a melting temperature or higher to polymerize the vinyl monomer. In the method for producing a modified propylene-based polymer, a method for producing a modified propylene-based polymer, characterized in that a powdery granular propylene-based polymer having a specific surface area of 0.1 m ² / g or more is used, preferably a ratio The present invention is characterized in that a vinyl-based monomer containing aromatic vinyl as a main component is pre-mixed with a radical polymerization initiator if necessary, to a powdery propylene-based polymer having a surface area of 0.2 m ² / g or more. Of the modified propylene polymer, (a) a granular propylene polymer having a specific surface area of 0.1 m ² / g or more, and (b) a vinyl polymer containing an aromatic vinyl monomer as a main component. Monomer 5 wt% or more (with the propylene-based polymer (C) in total weight) and (c) radical polymerization initiator are mixed, the polymer is substantially impregnated with the vinyl-based monomer and the radical polymerization initiator, and then melt-kneaded to form a vinyl-based monomer. It is intended to provide a modified propylene-based polymer composition characterized by being obtained by a polymerization reaction.

(Structure) The powdery and granular propylene-based polymer having a specific surface area of 0.1 m ² / g or more, which is used in the practice of the present invention, is mainly composed of propylene homopolymer and this propylene. It refers to copolymers with other olefins or ethylenically unsaturated monomers (all of them are copolymers containing 75% by weight or more of propylene), such as Ziegler-Natta catalysts and Kaminsky. It may be polymerized with any catalyst system such as a catalyst,
Specifically, isotactic polypropylene, crystalline propylene-ethylene copolymer, crystalline propylene-butene copolymer, maleic anhydride-modified polypropylene and the like are typical examples of the propylene-based polymer. It is also possible to use a mixture of two or more of these propylene-based polymers. If the crystallinity of the propylene-based polymer is low or the copolymerization component ratio is high, that is, if it is 25% by weight or more (when the propylene component is less than 75% by weight), it is easily dissolved in the vinyl monomer and the preliminary mixture becomes sticky. It is not preferable because it becomes a lump and becomes difficult to supply to an extruder or the like. Therefore, it is preferably a propylene homopolymer, a propylene copolymer containing 75% by weight or more of a propylene component, or a mixture thereof.

The propylene-based polymer has a powdery appearance and is fine as particles, and the particle size is preferably from 10 μm to
2 mm, when the particle size is large, it is porous. In addition, it is necessary to have a large specific surface area and to have a specific surface area of 0.1 m ² / g or more, preferably 0.2 m ² / g, in order to adsorb them without being dissolved in vinyl monomers. And above,
It is more preferably 0.3 m ² / g or more. Specific surface area is 0.1
If it is less than m ² / g, it takes time to impregnate the vinyl monomer at room temperature, the reactive extrusion processability of the propylene polymer in the extruder deteriorates, and the compatibility tends to become nonuniform, resulting in poor transparency and rigidity. Inferior and not preferable. Examples of the propylene polymer having a large specific surface area include Acurel PP manufactured by AKZO (Netherlands) and Spheripol PP manufactured by HIMONT (Italy).

Further, in the present invention, other powdery polymers which are difficult to dissolve in vinyl monomers can be used within a range that does not impair the properties of the powdery granular propylene polymer.
However, a radical-crosslinkable powdery polymer such as polyethylene causes an increase in kneading torque due to reticulation during melt-kneading, and therefore it is preferably half or less.

The vinyl-based monomer impregnated in the powdery or granular propylene-based polymer according to the present invention is a liquid at room temperature and contains an aromatic vinyl monomer as a main component and other vinyl monomers. You may have. Examples of the aromatic vinyl monomer include styrene, methylstyrene, vinyltoluene, vinylxylene, ethylvinylbenzene, isopropylstyrene, chlorostyrene, dichlorostyrene, and bromostyrene, which may be used alone or in combination. Such an aromatic vinyl monomer has an advantage of suppressing a decrease in the molecular weight of the propylene-based polymer, which is a problem when melt-kneading polymerization is performed, and improving mechanical properties such as rigidity.

In addition to the aromatic vinyl monomer as the main component, other vinyl monomers copolymerizable with the aromatic vinyl monomer, such as acrylonitrile, can be used as the vinyl monomer. Various vinyl cyanides; various vinyl esters such as vinyl acetate; acrylic acid or methacrylic acid or their alkyl esters or glycidyl esters, and further maleic acid may be used in combination.

Particularly, it is preferable to use a vinyl monomer having a functional group capable of forming a hydrogen bond in combination with an aromatic vinyl monomer in order to increase the polarity of the graft polymer and improve the printability and adhesiveness. As the polar functional group-containing vinyl monomer used in combination, copolymerizable epoxy group-containing vinyl monomer, hydroxyl group-containing vinyl monomer, carboxyl group-containing vinyl monomer, oxazoline group-containing vinyl monomer, silanol Examples include group-containing vinyl monomers. Preferably, it is an epoxy group-containing vinyl monomer or a carboxyl group-containing vinyl monomer.

As the epoxy group-containing vinyl monomer, for example, glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether, methacryl glycidyl ether and the like can be used alone or in combination. Glycidyl methacrylate is particularly preferable.

Examples of the hydroxyl group-containing vinyl monomer include 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate and 2
-Hydroxybutyl methacrylate and the like can be used alone or in combination.

Examples of the silyl group-containing vinyl monomer include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, vinyltris ( 2-methoxyethoxy) silane and the like can be used alone or in combination.

The carboxyl group-containing vinyl monomer includes, for example, acrylic acid, methacrylic acid, maleic anhydride, maleic acid and the like and alkyl esters thereof, and these are used alone or as a mixture.

As the oxazoline group-containing vinyl monomer, 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-oxazoline, etc. There is.

The amount of the vinyl-based monomer used is 5% by weight or more in the total weight with the powdery propylene-based polymer,
It is preferably 5 to 50% by weight. The amount of the aromatic vinyl monomer in the vinyl-based monomer is 50% by weight or more, preferably 80% by weight or more. The amount of aromatic vinyl monomer is
In order to prevent the low molecular weight of the modified propylene polymer,
When other vinyl monomers are used in combination, the amount is more than the addition amount, preferably 1 to 5 times.
It should be noted that monomers other than aromatic vinyl should be used to the extent that the resulting modified propylene-based polymer does not have a large adverse effect on the molecular weight reduction, tackiness, hygroscopicity, mechanical properties and the like.

The above-mentioned radical polymerization initiator is easily dissolved in aromatic vinyl due to the characteristics of the present invention, and has a half-life of 1 minute for polymerization at the melt-kneading temperature of the propylene-based polymer. Decomposition temperature to obtain 130 ℃
It is above, and preferably in the range of 175 to 250 ° C.

Among the radical polymerization initiators, particularly typical examples are t-butyl peroctate, dicumyl peroxide, tert-butyl perbenzoate, and dimethyl-di (tert-butyl peroxy) hexane. , Bis (tert-butylperoxyisopropyl) benzene, dimethyl-di (tert-butylperoxy) hexyne, diisopropylbenzene hydroperoxide or cumene hydroperoxide.

The amount of the radical polymerization initiator used is preferably 0.1 to 10 parts by weight, and particularly preferably, 100 parts by weight of the vinyl monomer.
A range of 1 to 5 parts by weight is suitable.

Further, since polypropylene has a radical disintegration property greatly different from that of polyethylene,
In carrying out graft polymerization, it is desirable to add a so-called stabilizer. However, it goes without saying that it is necessary to consider the kind and addition amount so as not to interfere with the polymerization of the vinyl-based monomer in use.

[0029] To exemplify only particularly representative stabilizers of this kind, pentaerythrityl-tetrakis ((di-tert-butyl-hydroxyphenyl) propionate), octdecyl (di-tert-butyl-). Various hindered phenolic stabilizers such as hydroxyphenyl) propionate, thiobis (methyl t-butylphenol) or trimethyl-tris (di-tert-butylhydroxybenzyl) benzene;
Various phosphorus stabilizers such as tetrakis (di-tert-butylphenyl) biphenylene phosphite or tris (di-tert-butylphenyl) phosphite; various metallic soaps such as zinc stearate or calcium stearate; Alternatively, there are various antacid adsorbents such as magnesium oxide or hydrotalcite.

The amount of the stabilizer used is usually 0.0 with respect to 100 parts by weight of the powdery propylene polymer.
Within the range of 1 to 1 part by weight, preferably 0.05 to 0.
A range of 5 parts by weight is suitable.

Furthermore, a small amount of solvent or water may be added as an additive for the purpose of diluting or deaerating the monomers or radical initiators.

In the present invention, the vinyl monomer and the radical polymerization initiator are substantially impregnated in the powdery propylene polymer. This impregnation is carried out under the conditions of temperature and time at which the vinyl monomer does not polymerize, and when the radical polymerization initiator is used in combination, the impregnation is carried out under the conditions of temperature and time so that the decomposition thereof does not substantially occur. Be seen.

In the impregnation of the vinyl-based monomer and the radical polymerization initiator, the modified propylene-based polymer is more homogenized to improve the physical properties such as transparency, and the preliminary mixture is put into a melt-kneader such as an extruder. Since the fluidity for smooth supply is required, the angle of repose of the powdery granular propylene-based polymer pre-mixture impregnated with them is preferably 70 ° or less,
A more preferable range is 35 to 60 °.

In general, the angle of repose (spatula angle) is an index showing the fluidity of a granular material in the powder industry, and the spatula is inserted into the powder of the sample so as to have a constant thickness.
Then, the spatula is pulled up to show the angle of the bottom of the chevron-shaped sample (powder and industrial Vol 9, No.
1, P61-72, 1977). It is usually measured at room temperature with a powder tester (Hosokawa Micron Powder Engineering Laboratory).

When the angle of repose is within the above range, the impregnated powdery propylene polymer has good fluidity and is preferable in terms of supplying it to the melt-kneading device.

In the impregnation operation of the present invention, the impregnation temperature is 100 ° C. or less, preferably 80 to 20 ° C., and 50 to 20 ° C. to prevent volatilization of the vinyl monomer.
Is more appropriate, and the impregnation time is 5
Minutes or more are preferable, and the range of 10 to 60 minutes is more suitable. Further, such impregnation is preferably carried out in a closed system using a mixer such as a Henschel mixer, or in an atmosphere of an inert gas such as nitrogen.

When the powdery granular propylene polymer impregnated with a vinyl monomer is melt-kneaded to polymerize the vinyl monomer, various closed containers such as Banbury and extruders are used. It can be performed by using various melt-kneaders capable of continuous production. As a melt-kneader, when considering so-called industrial production such as granulation, it is preferable to use an extruder, and it is easy to control the biting property of raw materials and the polymerization time. From the aspect, it is preferable to use a twin-screw extruder.

A preferred method for producing a modified propylene-based polymer is to supply a granular propylene-based polymer impregnated with a vinyl-based monomer or the like to an extruder and pressurize it while
It is preferable to heat the mixture within a range of 50 to 250 ° C. to melt the propylene-based polymer, polymerize the vinyl-based monomer, and then discharge the vinyl-based monomer from the die.

At this time, the vinyl-based monomer is mixed with the propylene-based polymer in advance and sufficiently impregnated before it is supplied to the extruder. May be fed from the liquid feeder to the molten propylene polymer.

When the radical polymerization initiator is used in combination, it is preferable that the radical polymerization initiator is dissolved in the vinyl monomer in advance and then added.
It may be added from a liquid injection pump to the propylene polymer containing a vinyl monomer in a molten state. Further, when a stabilizer is used in combination, it is preferable to preliminarily mix it with the powdery propylene polymer.

In the present invention, when a vinyl monomer is usually polymerized in the presence of a radical initiator, the propylene polymer in a molten state is sufficiently contacted with the vinyl monomer to be mixed. A polymer (graft polymer) in which a polymer derived from a vinyl monomer is grafted onto a propylene polymer may be produced. Unlike ethylene-based polymers, propylene-based polymers are usually radical-disintegrating polymers. Therefore, if they are simply melt-heated, molecular cleavage tends to occur, but in the presence of vinyl-based monomers containing aromatic vinyl, etc. On the contrary, by carrying out the melting and heating with, the graft reaction is likely to occur while preventing reticulation.

The obtained modified propylene-based polymer, which is composed of a propylene-based polymer component and an aromatic vinyl-based polymer component, is homogeneous and, as it is, as a molded product or pellet. Can be taken out as.

Thus, since the modified propylene-based polymer itself is a thermoplastic resin which is excellent in heat resistance, rigidity, moisture resistance and surface property, it can be used for food packaging, containers, various housings and the like. It can be used for various purposes. further,
Since the modified propylene-based polymer is composed of polar and non-polar parts, it can be used as a compatibility improver of various polymers (polymers or resins) or with an inorganic filler (inorganic filler). It is also excellent as a compatibility improver with other agents.

The modified propylene-based polymer obtained in the present invention includes reinforcing fibers such as glass fiber, carbon fiber and Kevlar fiber, inorganic fillers such as calcium carbonate, silica, mica and aluminum hydroxide, organic / inorganic. Pigments, dyes, etc. can be added. These additives may be mixed in advance with the powdery propylene-based polymer as long as the effects of the present invention are not impaired, and when the powdery propylene-based polymer impregnated with the vinyl-based polymer is melt-kneaded. May be added to.

[0045]

EXAMPLES Next, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In the following, all parts and% are by weight unless otherwise specified.

(Example 1) "Acurel PP" having a specific surface area of 31 m ² / g in a 10 liter Henschel mixer
800 of [Powdered polypropylene produced by AKZO]
Part, 0.4 parts of "Irganox 1010" (stabilizer manufactured by Ciba-Geigy, Switzerland), "Phosphite 1"
68 "(stabilizer from Ciba Geigy) and 0.8 part of calcium stearate. A mixture of 200 parts of styrene and 2 parts of "Perhexin 25B" (polymerization initiator manufactured by NOF CORPORATION) was added to the above powdery polypropylene compound, and the mixture was mixed at 40 ° C for 1 hour.
Mix at a speed of 500 times / minute for a certain time (3,
The mixture was sampled every 5 and 10 minutes, and the angle of repose was measured with a powder tester. The relationship between the angle of repose and the mixing time was graphed from the data of three points, the time at which the angle of repose reached 60 ° was determined, and this was taken as the impregnation required time. The composition having an angle of repose of 60 ° was continuously and smoothly supplied to an extruder or the like.

Similarly, "Acurel PP" [AKZ
[Provic Granule], which has the same specific surface area of 0.2 m ² / g
The time required for impregnation at which the angle of repose was 60 ° was determined in the same manner as in Example 1 except that the same amount of PN230 ”[powdered-grain polypropylene manufactured by Tokuyama Soda Co., Ltd.] was used. Furthermore, "Acurel PP" and "Provic Granule PN230"
Were mixed at the ratios shown in Table 1, and the required time for impregnation at which the angle of repose was 60 ° was determined in the same manner, and the results are shown in Table 1. From the results, the relationship between the specific surface area of polypropylene and the time required for impregnation is shown in FIG.

[0048]

[Table 1]

(Example 2) "Acurel PP" having a specific surface area of 31 m ² / g was added to a 10-liter Henschel mixer.
800 of [Powdered polypropylene produced by AKZO]
Part, 0.4 parts of "Irganox 1010" (stabilizer manufactured by Ciba-Geigy, Switzerland), "Phosphite 1"
68 "(stabilizer from Ciba Geigy) and 0.8 part of calcium stearate. A mixture of 200 parts of styrene and 2 parts of "Perhexin 25B" (polymerization initiator manufactured by NOF CORPORATION) was added to the above powdery polypropylene compound, and the mixture was mixed at 40 ° C for 3 times.
Mix for 0 minutes.

The obtained composition had an angle of repose of 48 ° as measured by a powder tester, and the composition was continuously and smoothly fed to an extruder or the like.

Then, the blend was heated to a barrel temperature of 200.
℃ (however, the feeder part is 180 ℃), the die temperature was supplied to a 30 mm twin-screw extruder with a fixed feeder (manufactured by Brabender, Germany) set to 210 ℃, 2 per minute
Melt kneading was performed at a speed of 0 rotation to polymerize styrene, and the modified propylene-based polymer was taken out as pellets. The pellets obtained are IS50 manufactured by Toshiba Machine Co., Ltd.
Using an AM injection molding machine, a test piece (test piece) was prepared under the condition that the resin temperature was 230 ° C. For this sample,
Various physical properties were measured and evaluated.

In addition, the above pellets were analyzed by infrared spectroscopic analysis to give 700 cm -1 (attribution to styrene) and 13
The styrene content was measured from a calibration curve based on the ratio to 80 cm -1 (attributed to polypropylene), and the value was used to determine the polymerization rate of styrene. Furthermore, in order to judge the presence or absence of polystyrene graft, polypropylene is not dissolved, but polystyrene is dissolved in tetrahydrofuran as a solvent, pellets are placed, and Soxhlet extraction is performed under reflux to remove residual styrene moieties in the pellets. The graft rate was also measured from the rate. The above measurement results are shown in Table 2.

The polymerization rate was 90% or more so that the monomer recovery treatment was not particularly required, and the rigidity rate was 10% higher than that of the single polypropylene (unmodified polypropylene). It is known that the target value to be increased by more than 100% was achieved and the rigidity was improved. In addition, transparency is also acceptable as a packaging material.
The transmittance was 5% or more, and the heat deformability was 130 ° C. or more, which is required for a microwave oven reheating container. The moisture permeability was almost the same as that of the single polypropylene and, of course, far better than that of polystyrene.

(Comparative Example 1) In Example 1, instead of 800 parts of "Acurel PP" [powder granulated polypropylene manufactured by AKZO], "Tokuyama Polypro MS23" was used.
0 "[Polypropylene in pellet form manufactured by Tokuyama Soda Co., Ltd.]
Mixing was performed in the same manner as in Example 1 except that the same amount was used,
Add 200 parts of styrene with 2 parts of "Perhexin 25B" [NOF CORPORATION] with a Henschel mixer, add to the above-mentioned pellet polypropylene composition, and mix at 50 ° C for 30 minutes. However, since pelletized polypropylene did not absorb styrene, styrene and the like began to separate and start to flow away, so the mixing was abandoned and stopped without stopping.

Comparative Example 2 A 30 mm twin-screw extruder in which "Tokuyama Polypro MS230" [a pelletized polypropylene manufactured by Tokuyama Soda Co., Ltd.] used in Comparative Example 1 was set under the same temperature conditions as in Example 1 "Perhexin 25B" [Nippon Yushi-Seiyaku Co., Ltd.] was fed into the (Bravender, Germany) at a rate of 800 parts per hour by a quantitative feeder, and melt-kneaded at a speed of 20 rotations from the middle of the extruder.
Styrene mixed with 1% of [Product] was injected at a rate of 200 parts per hour by a liquid injection pump. Melt kneading was carried out in the same manner as in Example 1 to polymerize styrene, and the modified propylene-based polymer was taken out as pellets. Using the obtained pellets, an injection molding machine was used in the same manner as in Example 1 to prepare a test piece (test piece) under the condition that the resin temperature was 230 ° C.
Various physical properties of this test piece were measured and evaluated.

The blend was melt-kneaded in an extruder in the same manner as in Example 2 to obtain a modified propylene polymer, which was analyzed and various physical properties were measured.
The measurement results are shown in Table 2.

The polymer obtained had a degree of polymerization of less than 90% and a degree of grafting of less than 20%. In addition, the transparency required for the packaging material was also less than 65%. Probably because of this, even if the rigidity is lower than 10% compared with the case of the single polypropylene, there was only a low improvement effect.

(Example 3) "Accurrel PP" having a specific surface area of 31 m ² / g in Example 2 [manufactured by AKZO,
Specific surface area of 0.2 instead of powdered polypropylene
A powder-granular blend was obtained in the same manner as in Example 2 except that the same amount of "Provic Granule PN230" [powder-granulated polypropylene manufactured by Tokuyama Soda Co., Ltd.] of m ² / g was used.

The obtained composition had an angle of repose of 65 ° as measured by a powder tester, and the composition could be continuously supplied to an extruder or the like.

Next, the blend was heated to a barrel temperature of 200.
℃ (however, the feeder part is 180 ℃), the die temperature was supplied to a 30 mm twin-screw extruder with a fixed feeder (manufactured by Brabender, Germany) set to 210 ℃, 2 per minute
Melt kneading was performed at a speed of 0 rotation to polymerize styrene, and the modified propylene-based polymer was taken out as pellets. The pellets obtained are IS50 manufactured by Toshiba Machine Co., Ltd.
Using an AM injection molding machine, a test piece (test piece) was prepared under the condition that the resin temperature was 230 ° C. For this sample,
Various physical properties were measured and evaluated.

Then, a modified propylene polymer was obtained in the same manner as in Example 2 with respect to the compound, and the modified propylene polymer was analyzed and various physical properties were measured. The measurement results are summarized in Table 2.

The obtained modified propylene polymer had a polymerization rate of 90% or more. The rigidity was also much improved, being 10% or more compared to the single polypropylene. The transparency was 65% or more, which was acceptable as a packaging material, and the heat-deformability was 130 ° C or more, which is required for a microwave oven reheating container. It was

(Example 4) "Acurel PP" having a specific surface area of 31 m ² / g in Example 2 [manufactured by AKZO,
Instead of [powdered polypropylene], "Acurel P
P "and" Provic Granule PN230 "[powder granules manufactured by Tokuyama Soda Co., Ltd.] were mixed in a ratio of 1: 9, and the same powder granules having an average specific surface area of 0.4 m ² / g were obtained. A powdery and granular composition was obtained in the same manner as in Example 2 except that the amounts were used.

The obtained compound had an angle of repose of 58 ° as measured by a powder tester, and the compound could be continuously and smoothly supplied to an extruder or the like.

Next, the blend was heated to a barrel temperature of 200.
℃ (however, the feeder part is 180 ℃), the die temperature was supplied to a 30 mm twin-screw extruder with a fixed feeder (manufactured by Brabender, Germany) set to 210 ℃, 2 per minute
Melt kneading was performed at a speed of 0 rotation to polymerize styrene, and the modified propylene-based polymer was taken out as pellets. The pellets obtained are IS50 manufactured by Toshiba Machine Co., Ltd.
Using an AM injection molding machine, a test piece (test piece) was prepared under the condition that the resin temperature was 230 ° C. For this sample,
Various physical properties were measured and evaluated.

Then, modified propylene-based polymers were obtained in the same manner as in Example 2 for both the blends, and the modified propylene-based polymers were analyzed and various physical properties were measured. The measurement results are summarized in Table 1.

The obtained modified propylene polymer had a polymerization rate of 90% or more. The rigidity was also much improved, being 10% or more compared to the single polypropylene. The transparency was 65% or more, which was acceptable as a packaging material, and the heat-deformability was 130 ° C or more, which is required for a microwave oven reheating container. It was

(Example 5) "Acurel PP" having a specific surface area of 31 m ² / g in Example 1 [manufactured by AKZO,
Of 800 parts of powdered polypropylene] to 600 parts, and 0.3 parts of "Irganox 1010" (product of Ciba-Geigy, Switzerland) and "Phosphite 168" (product of Ciba-Geigy) 0.3 parts and 0.6 parts of calcium stearate were mixed. Furthermore, 200 parts of styrene was added to 400 parts of "Perhexin 25
B ”[Nippon Yushi Co., Ltd. product], mixed with 3 parts, was added to the powdered polypropylene compound described above, and the mixture was heated to 50 ° C.
And mixed for 30 minutes.

The obtained composition had an angle of repose of 57 ° as measured by a powder tester, and the composition was continuously and smoothly supplied to an extruder or the like.

The formulation is then charged to a barrel temperature of 200.
℃ (however, the feeder part is 180 ℃), the die temperature was supplied to a 30 mm twin-screw extruder with a fixed feeder (manufactured by Brabender, Germany) set to 210 ℃, 2 per minute
Melt kneading was performed at a speed of 0 rotation to polymerize styrene, and the modified propylene-based polymer was taken out as pellets. The pellets obtained are IS50 manufactured by Toshiba Machine Co., Ltd.
Using an AM injection molding machine, a test piece (test piece) was prepared under the condition that the resin temperature was 230 ° C. For this sample,
Various physical properties were measured and evaluated.

With respect to the compound, modified propylene-based polymers were obtained in the same manner as in Example 1, and the analysis and the measurement of various physical properties were performed. The measurement results are summarized in Table 1.

The modified propylene polymer obtained had a polymerization rate of 90% or more. The rigidity was also much improved, being 10% or more compared to the single polypropylene. The transparency was 65% or more, which was acceptable as a packaging material, and the heat-deformability was 130 ° C or more, which is required for a microwave oven reheating container. It was

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[Table 2]

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[Table 3]

<< Footnote in Table >>"PP" in the table is an abbreviation for "polypropylene". Further, the "styrene preparation ratio" is "%" in the weight sum with polypropylene.

Further, as a method of evaluating various physical properties,
It is as follows. Specific surface area: The measurement was performed using a monosorb (surface area measuring device: Yuasa Ionics Inc.). Angle of repose: The measurement was performed using a powder tester (Hosokawa Micron Co., Ltd.) in accordance with the same regulations, and displayed in (degrees). Thermal deformability ... The measurement was carried out by displaying in Vicat temperature (° C.) according to JIS K-7202, and the load was 1 kg. Rigidity ... The measurement was performed according to JIS K-7203, and it was displayed in (10 ⁴ kg / cm ² ). Transparency: A 300 μm-thick sheet produced by hot pressing was measured with a haze meter and displayed as (%). Reactive extrusion processability: ◎: angle of repose of impregnated powdered PP compound is less than 60 degrees, ○: 〃 angle of repose is 60 to 70 degrees ×: 〃 angle of repose is more than 70 degrees

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Industrial Applicability According to the present invention, an aromatic vinyl-based monomer is premixed with a powdery or granular propylene-based polymer having a specific surface area and then kneaded and melted to polymerize the aromatic vinyl-based monomer. This makes it possible to facilitate impregnation at room temperature, increase the amount of vinyl monomer components, and also provide excellent reactive extrusion processability in an extruder, etc., and the high polymerization rate and graft rate of vinyl monomers. The compatibility of the modified propylene-based polymer is excellent,
Therefore, it is possible to provide a thermoplastic molding material which is excellent in transparency and rigidity and which is useful as a packaging material / container material having extremely high practicality.

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[Brief description of drawings]

FIG. 1 is a diagram showing the relationship between the impregnation time and the specific surface area of a polypropylene polymer according to Example 1 of the present invention.

Claims (8)

[Claims] 1. A method for producing a modified propylene-based polymer, wherein a vinyl-based monomer is premixed with a propylene-based polymer, and the pre-mixture is kneaded at a melting temperature or higher to polymerize the vinyl-based monomer. A method for producing a modified propylene-based polymer, which comprises using a powdery or granular propylene-based polymer having a specific surface area of 0.1 m ² / g or more. 2. A powdery propylene-based polymer having a specific surface area of 0.2 m ² / g or more.
A method for producing a modified propylene-based polymer. 3. The propylene-based polymer has a specific surface area of 0.3 m.
^The method for producing a modified propylene-based polymer according to claim 1, which is a powdery or granular propylene-based polymer having a content of ² / g or more. 4. The method for producing a modified propylene polymer according to claim 1, wherein the vinyl monomer is an aromatic vinyl monomer. 5. The modified propylene polymer according to claim 1, wherein the vinyl-based monomer is composed of an aromatic vinyl monomer and the same amount or less of another vinyl monomer. Law. 6. The method for producing a modified propylene-based polymer according to claim 1, wherein the vinyl-based monomer is 5% by weight or more (in the total weight with the propylene-based polymer). . 7. (a) a granular propylene polymer having a specific surface area of 0.1 m ² / g or more, and (b) a vinyl monomer containing an aromatic vinyl monomer as a main component in an amount of 5% by weight or more. After mixing (in the total weight with the propylene-based polymer) and (c) a radical polymerization initiator, and substantially impregnating the polymer with a vinyl-based monomer and a radical polymerization initiator,
A modified propylene polymer composition obtained by melt-kneading and polymerizing a vinyl monomer. 8. The modified propylene-based polymer composition according to claim 6, which is used for packaging materials and container materials.